As of 2019, only five space probes are leaving the solar system: Pioneer 10, Pioneer 11, Voyager 1, Voyager 2 and New Horizons. The Voyagers already left the solar system and entered the interstellar space (Voyager 1 on August 25, 2012, and Voyager 2 on November 5, 2018. The others also will leave the heliosphere Notes 1 and reach the interstellar space in a few years.

The speed of light is the Universal speed limit – nothing can travel faster than light. In the vacuum (commonly denoted c), its exact value is 299,792,458 meters per second (around 186,000 miles per second). In other words, if you could travel at the speed of light, you could go around the Earth 7.5 times in one second.

Our planet is getting warmer, with an increasing pace. This month, there were three bad, very bad news about global warming. According to a study published in Proceedings of the National Academy of Sciences, Antarctica is losing six times more ice mass annually now than 40 years ago. Another study, published in the scientific journal Advances in Atmospheric Sciences concluded that 2018 was the hottest year ever recorded for the Earth’s oceans. And, according to researchreleased in the online journal Nature Communication, Permafrost is warming at a global scale – the temperature of the frozen ground in continuous permafrost zones rose by an average of 0.3 degrees Celsius between 2006 and 2017.

Scientists from the China National Space Administration (CNSA) has confirmed that the seedlings taken to the far side of the moon with Chang’e 4 lunar lander have started sprouting. Or to put it another way: this is the first time something has been grown on an astronomical body outside of the Earth! Now we have “moon plants”!

Margaret Hamilton is not only one of the first software developers, but she also literally created the term “Software Engineering” to describe her work. The code she wrote successfully put humans on the moon for the first time.

A beautiful photo showing the first flower grown in space (a zinnia flower) with our beautiful Earth in the background. Now retired NASA astronaut Scott Kelly shared photographs of a blooming zinnia flower in the Veggie plant growth system aboard the International Space Station on his Twitter account back in 2016.

The world has been urbanizing rapidly in recent decades. In 1950, only 30 percent of the world’s population lived in urban areas, a proportion that grew to 55 percent by 2018. The global urbanization rate masks important differences in urbanization levels across geographic regions.

Northern America is the most urbanized region, with 82 percent of its population residing in urban areas, whereas Asia is approximately 50 percent urban, and Africa remains mostly rural with 43 percent of its population living in urban areas in 2018 (United Nations, 2018).

"Consider again that dot [Earth]. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam." ~Carl Sagan, Pale Blue Dot: A Vision of the Human Future in Space

“We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special.” ~Stephen Hawking

“And yet it moves.” ~Galileo Galilei

“I believe in evidence. I believe in observation, measurement, and reasoning, confirmed by independent observers. I’ll believe anything, no matter how wild and ridiculous, if there is evidence for it. The wilder and more ridiculous something is, however, the firmer and more solid the evidence will have to be.” ~Isaac Asimov

“Scientists don’t protect their ideas, they crash-test them and see if they make it.”

“For me, questions like:

-what is our Universe? -what is it made of? -where did it originate? -what is its ultimate fate?

are some of the most interesting and fascinating ones humanity can conceive of. For millennia, these were questions for poets, philosophers, and theologians. We couldn’t come up with hard answers, so all we had were stories.

Those days are long behind us. For the first time, owing to the science of cosmology, we know the answer to these and many others. There are still unknowns, of course, and open questions that have been raised by the answers we’ve uncovered so far.

We’d be foolish to stop now. We’ve come so far. I want to know the next answers, to take the next steps, and to marvel at the implications of the best answers we’ve uncovered so far.” ~Ethan Siegel